首先介绍了MPEG－2音频layer Ⅲ（MP3）的解码算法，详细地叙述进行定点C语言仿真的技巧。基于TI公司的’C549　DSP芯片进行汇编工作，在TMS320C549　EVM板上实现了网上MP3文件的连续播放，效果满意。经过对算法和程序的优化使所需的运算量和存储空间都很低，使能在TI公司的低价型’C5402　DSP上实现。-First introduced the MPEG-2 audio layer Ⅲ (MP3) decoding algorithm, a detailed account of the fixed-point C-simulation techniques. Based on TI' s'　C549 DSP chip assembly work in TMS320C549 EVM board to achieve an online MP3 file of continuous playback, the effect is satisfactory. After the optimization of algorithms and procedures to make the necessary computation and storage space are very low, so low in TI' s type ' C5402 DSP to achieve.